Virtual universes or virtual worlds are computer-based simulated environments intended for its users or residents to inhabit and interact via avatars, which are personas or representations of the users of the virtual universes. One example of a virtual universe is Second Life, which is a trademark of Linden Research Inc. in the United States. Avatars in these types of virtual universes, which can number well over a million, have a wide range of business and social experiences.
Many regions within a virtual universe contain complex environments with a large number of objects. In the prior art, virtual universes cache content from the virtual universe to increase the speed in which a region may be rendered. However, prolonged caching of unneeded objects consumes constrained resources of servers, cache appliances, clients, etc., while premature expiration of content degrades user experience as required objects must be reacquired. Methods such as Least Recently Used (LRU) and First-In-First Out (FIFO) to expire content from caches are well known in the art. However these methods are not effective because such methods are not optimal for use in virtual universes.